Add proxy server feature.

[Darkclainer]

Now in configuration in "proxy" section you can specify two new options:

1. url - is a proxy url
2. mode - it is string, one of "all", "missing", "none"

Issue #33

[ghost]

Found some fixes!

P.S. share your ideas, feedbacks or issues with us at https://github.com/fixmie/feedback (this message will be removed after the beta stage).

[ghost]

existing comment doesn't match identifier "ProxyNone"

Suggested change

	// Proxy server is off
	// ProxyNone server is off

[ghost]

existing comment doesn't match identifier "ProxyMissing"

Suggested change

	// Only missing requests are proxied
	// ProxyMissing missing requests are proxied

[ghost]

existing comment doesn't match identifier "ProxyAll"

Suggested change

	// All requests are proxied
	// ProxyAll requests are proxied

[codecov-io]

Codecov Report

Merging #41 into master will increase coverage by 1.3%.
The diff coverage is 100%.

@@           Coverage Diff            @@
##           master     #41     +/-   ##
========================================
+ Coverage      91%   92.3%   +1.3%     
========================================
  Files           6       7      +1     
  Lines         189     221     +32     
========================================
+ Hits          172     204     +32     
  Misses         14      14             
  Partials        3       3

Impacted Files	Coverage Δ
internal/server/http/server.go	86.58% <100%> (+1.65%)	⬆️
internal/config.go	100% <100%> (ø)	⬆️
internal/server/http/proxy.go	100% <100%> (ø)

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[aperezg]

Can you check it, @joanlopez?

[aperezg]

Suggested change

	type ProxyMode int
	type ProxyMode uint8

[Darkclainer]

Why do we need specifically uint8?

[aperezg]

we prefer declare the enums with a more accurate type possible as standard, 8bits is more than enough to a enum and in most case u don't need negative numbers, so uint8 is a elegant solution

[aperezg]

you need to update the headers to allow for SSL redirection:

                r.URL.Host = p.url.Host
		r.URL.Scheme = p.url.Scheme
		r.Header.Set("X-Forwarded-Host", r.Header.Get("Host"))
		r.Host = p.url.Host

For that you will need to persist the result of url.Parse into the proxy struct.

[aperezg]

I tested with the comment that I suggested and, all working very fine :)

[aperezg]

All options that we include on the config file, usually are on the command line also.

I think that you could add something like that:
-proxy-url="https://swapi.co" -proxy-mode=missing

And if the proxy-mode is not declare using by default none, and if the proxy_mode != none and proxy_url is not defined get an early error and close the application.

[aperezg]

Could you update the README.md with how to use the proxy?

In the section Using Killgrave

Below to the sentence: "Or custome your server with this flags:" we're printing an output of the help command, so when you've added your new flags, you will need to update this with your output, as now.

And in the section "Use killgrave with config file:"

Modify the example with the proxy, i.e:

#config.yml

imposters_path: "imposters"
port: 3000
host: "localhost"
proxy:
  url: https://example.com
  mode: missing
cors:
  methods: ["GET"]
  headers: ["Content-Type"]
  exposed_headers: ["Cache-Control"]
  origins: ["*"]
  allow_credentials: true

And if you want you could include a section like #CORS section, where you explain how the proxy works and which are the options to configure the proxy.

Thanks!

[aperezg]

Follow #44